Uma matéria interessante de The Economist que havia saido no dia 05/03 mas que só hoje tive acesso!
Mar 5th 2009
From The Economist print edition
Consumer electronics: A new push is under way to let mobile devices off the leash by doing away with their dependence on power cables
IF THE father of electromagnetism, Michael Faraday, could be transported into the 21st century, he would no doubt be awestruck by the iPhone. After five hours of tapping its touch-screen to browse the internet, make calls, play games and determine his location via satellite-positioning, he might also find himself a little puzzled. Why, with all the advances in technology and communications, would such a sophisticated device still need to be plugged in to be recharged? If phone calls and web pages can be beamed through the air to portable devices, then why not electrical power, too? It is a question many consumers and device manufacturers have been asking themselves for some time—and one that both new and established technology companies are now hoping to answer.
To seasoned observers of the electronics industry, the promise of wireless recharging sounds depressingly familiar. In 2004 Splashpower, a British technology firm, was citing “very strong” interest from consumer-electronics firms for its wireless charging pad. Based on the principle of electromagnetic induction that Faraday had discovered in the 19th century, the company’s “Splashpad” contained a coil that generated a magnetic field when a current flowed through it. When a mobile device containing a corresponding coil was brought near the pad, the process was reversed as the magnetic field generated a current in the second coil, charging the device’s battery without the use of wires. Unfortunately, although Faraday’s principles of electromagnetic induction have stood the test of time, Splashpower has not—it was declared bankrupt last year without having launched a single product.
Thanks to its simplicity and scalability, electromagnetic induction is still the technology of choice among many of the remaining companies in the wireless-charging arena. But, as Splashpower found, turning the theory into profitable practice is not straightforward. One of the main difficulties for companies has been persuading manufacturers to incorporate charging modules into their devices. But lately there have been some promising developments.
The first is the formation in December 2008 of the Wireless Power Consortium, a body dedicated to establishing a common standard for inductive wireless charging, and thus promoting its adoption. (It is modelled on a similar body that did the same for Bluetooth, a short-range wireless technology that is now found in most mobile phones.) The new consortium’s members include big consumer-electronics firms, such as Philips and Sanyo, as well as Texas Instruments (TI), a chipmaker.
Menno Treffers, chairman of the consortium and director of standardisation at Philips, says universal standards are the single most important requirement for the adoption of wireless charging. Philips is one of the few companies to have commercialised wirelessly charged devices—notably, electric toothbrushes and something it calls an “intimate dual massager”. But Mr Treffers acknowledges that a more collaborative approach is needed to ensure that different devices, such as mobile phones, laptops and digital cameras, can share the same charging equipment.
Fierce competition between manufacturers of mobile devices is also accelerating the introduction of wireless charging. The star of this year’s Consumer Electronics Show, an annual jamboree held in Las Vegas, was the Pre, a snazzy smart-phone from Palm (pictured left). As well as the standard arsenal of technical features—touch-screen, Wi-Fi, GPS, Bluetooth and built-in camera—the Pre also has an optional charging pad, called the Touchstone, which uses electromagnetic induction to charge the device wirelessly. When the device is placed on the pad, the two recognise each other through built-in sensors. Magnets embedded in the pad align the handset and hold it in place during charging.
Palm was not the only exhibitor in Las Vegas promoting wireless charging. Fulton Innovation, another member of the Wireless Power Consortium and the eventual owner of Splashpower’s assets, used the show to unveil a number of products including an in-car console equipped with inductive coils that can wirelessly charge mobile devices while on the road. (BMW says it will offer its 7 Series cars in South Korea with a wireless-recharging dock for one of Samsung’s handsets.) A modified toolbox from Bosch demonstrated the potential for wirelessly charging power tools.
Other domestic applications in the works include embedding charging pads into kitchen counters to enable the wireless use of blenders and other appliances. Bret Lewis of Fulton Innovation says his firm’s technology could also be used for industrial applications, or to charge electric cars. For the time being, however, the focus is on mobile phones, laptops and other consumer devices, and he sees 2009 as “the year for wireless”. That is probably too ambitious, but a third recent development suggests that the commercialisation of inductive charging may not be far off.
In November 2008 TI announced that it had joined forces with Fulton Innovations “to accelerate development of efficient wireless power solutions”. TI, which provides components to many of the world’s leading mobile-phone makers said it was exploring the production of integrated circuits that supported the technology developed by Fulton Innovations, with the aim of reducing the cost and size of the components needed for wireless charging and making it easier for device-makers to incorporate them into their products quickly.
“From a semiconductor and power-management point of view, wireless charging is a natural extension of what we have been doing,” says Masoud Beheshti, director of battery-charge management at TI. He predicts that, like Bluetooth, wireless charging will initially be offered on high-end devices, before gradually becoming more widely available.
As wireless-charging equipment based on electromagnetic induction heads towards the market, a number of alternative technologies are also being developed to transmit power over both short and long distances. WildCharge, a start-up based in Colorado, has already started selling a number of wireless-charging devices that take a cheaper but simpler approach in which mobile devices make electrical contact with a special charging pad via four small conductive metal studs (pictured).
WildCharge and the licensees of its technology have developed replacement back covers for a number of popular devices, including Motorola’s RAZR phones and video-game controllers for the Nintendo Wii and the Sony PlayStation 3. No matter how the device is plonked down, two of the bumps establish direct electrical contact with the pad. The firm has also developed special “skins” for Blackberry smart-phones, so that they too can be charged without the need for an adaptor. Although it may not have the “wow” factor of inductive coupling, this approach does away with the necessity for a “handshake” between the device and the pad, and with the need to align the device and the pad in a particular way before charging can begin.
At the other end of the spectrum is the idea of long-range transmission of wireless power, which could in principle do away with the need for a charging pad altogether. This technique uses the energy in radio waves, broadcast from a transmitter and harnessed by an antenna, to generate electricity. Using the passive-power principle found in crystal radios, the method has proved successful over short distances in places where it is difficult to replace batteries or carry out maintenance. The problem is that the intensity of the radio waves needed to charge mobile phones and laptop computers over long distances might be hazardous to human health, and regulators would be unlikely to approve.
Nevertheless a firm called Powercast, based in Pittsburgh, Pennsylvania, has developed wireless-charging products that can do useful things while still operating at safe power levels. Over distances of less than 1.5 metres, its technology can be used to run low-power lighting systems; at a range of up to three metres, the radio waves can provide useful power for trickle-charging rechargeable batteries; and up to about 7.5 metres, they can be used to power wireless sensor networks. The firm talks of providing “milliwatts over metres” and “watts over centimetres”.
Yet another approach is that taken by PowerBeam, a start-up based in Silicon Valley. It uses lasers to beam power from one place to another, but it too faces regulatory difficulties. The firm says the low power-density of its lasers and a series of safeguards ensures that human exposure remains within regulatory limits.
With so many companies working towards wireless power, how long will it be before the cord is finally cut? According to Charles Golvin of Forrester, a consultancy, one of the key considerations is getting manufacturers to abandon a lucrative line of business. He says that many mobile-phone manufacturers use the proprietary connectors on their chargers to retain customers, as people are more likely to buy products for which they already have charging adaptors at home, in the office, or in the car. This may make them reluctant to switch to a common wireless-charging standard. But Mr Colvin thinks strong demand will ensure that wireless technology prevails in the long run.
Peaks and troughs
Stephan Ohr of Gartner, a market-research firm, says the prospects for wireless power are realistic, but the path to widespread adoption will not be as easy as many in the industry expect. New technologies tend to go through a period of “inflated expectations” in which they are hyped, but fail to gain traction. Only after passing through the “trough of disillusionment”, during which expectations return to a more sensible level, are they widely adopted. For wireless charging, Mr Ohr expects this to take three to five years.
But it now seems to be a matter of when, rather than if, wireless charging enters the mainstream. And if those in the field do find themselves languishing in the trough of disillusionment, they could take some encouragement from Faraday himself. He observed that “nothing is too wonderful to be true if it be consistent with the laws of nature.” Not even a wirelessly rechargeable iPhone.